Instrument support holder



FIG. 1 is a perspective view of an instrument support holder;

FIG. 2 is a perspective view of the instrument support holder showing the instrument support holder from the opposite side;

FIG. 3 is a bottom end view of the suction cup portion only of the instrument support holder, the bottom portions of the other features not being part of the claimed design; and,

FIG. 4 is a top end view of the instrument support holder as shown in FIGS. 1 and 2. 

The ornamental design for an instrument support holder, as shown and described. 